AUTOMATED FLOW-INJECTION TECHNIQUE FOR USE IN DISSOLUTION STUDIES OF SUSTAINED-RELEASE FORMULATIONS - APPLICATION TO IRON(II) FORMULATIONS

The application of flow-injection analysis (FIA) to automated dissolut ion studies of sustained-release formulations is described. The long-t erm stability of the dissolution-FIA analyser was checked during unatt ended operation for 42 h. The construction of multiple calibration cur ves with the so-called electronic dilution FIA procedure was used to e xtend the linear range of the determination. The computer-controlled F IA system and the principles of associated software are described and applied to dissolution studies of sustained-release formulations of ir on(II) using its sensitive reaction with the colour reagent, ferrozine . The extended linear range of the determination is 1-130 ppm iron(II) and the precision (RSD) better than 3% (n = 3).